Automotive vehicles are conventionally powered via an internal combustion engine that acts as the sole source of the torque needed for propelling the vehicle. However, battery electric, hybrid electric, and extended-range electric vehicles all have emerged as viable fuel efficient alternatives to the conventional gas-powered vehicle. Unlike battery electric vehicles, hybrid electric and extend-range electric vehicles retain a gas engine as part of the powertrain. Strong hybrid electric vehicles continue to use engine torque for propulsion, for instance at higher speeds when electric motors become relatively inefficient. Mild/weak hybrid electric vehicles use a motor to start the engine after an autostop event, but otherwise power the vehicle conventionally.
An extended-range electric vehicle, unlike a typical strong or mild hybrid, uses a smaller gas engine as an electrical power generator when additional charging of an onboard battery module is required. An extended-range electric vehicle may use multiple electric traction motors as part of its powertrain. When the battery module is depleted, the engine may be automatically started and used to generate electrical energy. The electrical energy may be directed to the battery module and/or used to deliver input torque to a transmission depending on the mode. In this manner, the engine is used to extend the vehicle's effective electric operating range.